/**
 * Copyright (C) 2009, 2010 SC 4ViewSoft SRL
 *  
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *  
 *      http://www.apache.org/licenses/LICENSE-2.0
 *  
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.achartengine.model;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

import org.achartengine.util.MathHelper;

/**
 * An XY series encapsulates values for XY charts like line, time, area,
 * scatter... charts.
 */
public class XYSeries implements Serializable
{
	/** The series title. */
	private String			mTitle;
	/** A list to contain the values for the X axis. */
	private List<Double>	mX		= new ArrayList<Double>();
	/** A list to contain the values for the Y axis. */
	private List<Double>	mY		= new ArrayList<Double>();
	/** The minimum value for the X axis. */
	private double			mMinX	= MathHelper.NULL_VALUE;
	/** The maximum value for the X axis. */
	private double			mMaxX	= -MathHelper.NULL_VALUE;
	/** The minimum value for the Y axis. */
	private double			mMinY	= MathHelper.NULL_VALUE;
	/** The maximum value for the Y axis. */
	private double			mMaxY	= -MathHelper.NULL_VALUE;

	/**
	 * Builds a new XY series.
	 * 
	 * @param title the series title.
	 */
	public XYSeries(String title)
	{
		mTitle = title;
		initRange();
	}

	/**
	 * Initializes the range for both axes.
	 */
	private void initRange()
	{
		mMinX = MathHelper.NULL_VALUE;
		mMaxX = -MathHelper.NULL_VALUE;
		mMinY = MathHelper.NULL_VALUE;
		mMaxY = -MathHelper.NULL_VALUE;
		int length = getItemCount();
		for (int k = 0; k < length; k++)
		{
			double x = getX(k);
			double y = getY(k);
			updateRange(x, y);
		}
	}

	/**
	 * Updates the range on both axes.
	 * @param x the new x value
	 * @param y the new y value
	 */
	private void updateRange(double x, double y)
	{
		mMinX = Math.min(mMinX, x);
		mMaxX = Math.max(mMaxX, x);
		mMinY = Math.min(mMinY, y);
		mMaxY = Math.max(mMaxY, y);
	}

	/**
	 * Returns the series title.
	 * 
	 * @return the series title
	 */
	public String getTitle()
	{
		return mTitle;
	}

	/**
	 * Sets the series title.
	 * 
	 * @param title the series title
	 */
	public void setTitle(String title)
	{
		mTitle = title;
	}

	/**
	 * Adds a new value to the series.
	 * 
	 * @param x the value for the X axis
	 * @param y the value for the Y axis
	 */
	public void add(double x, double y)
	{
		mX.add(x);
		mY.add(y);
		updateRange(x, y);
	}

	/**
	 * Removes an existing value from the series.
	 * @param index the index in the series of the value to remove
	 */
	public void remove(int index)
	{
		double removedX = mX.remove(index);
		double removedY = mY.remove(index);
		if (removedX == mMinX || removedX == mMaxX || removedY == mMinY
				|| removedY == mMaxY)
		{
			initRange();
		}
	}

	/**
	 * Removes all the existing values from the series.
	 */
	public void clear()
	{
		mX.clear();
		mY.clear();
		initRange();
	}

	/**
	 * Returns the X axis value at the specified index.
	 * 
	 * @param index the index
	 * @return the X value
	 */
	public double getX(int index)
	{
		return mX.get(index);
	}

	/**
	 * Returns the Y axis value at the specified index.
	 * 
	 * @param index the index
	 * @return the Y value
	 */
	public double getY(int index)
	{
		return mY.get(index);
	}

	/**
	 * Returns the series item count.
	 * @return the series item count
	 */
	public int getItemCount()
	{
		return mX.size();
	}

	/**
	 * Returns the minimum value on the X axis.
	 * @return the X axis minimum value
	 */
	public double getMinX()
	{
		return mMinX;
	}

	/**
	 * Returns the minimum value on the Y axis.
	 * @return the Y axis minimum value
	 */
	public double getMinY()
	{
		return mMinY;
	}

	/**
	 * Returns the maximum value on the X axis.
	 * @return the X axis maximum value
	 */
	public double getMaxX()
	{
		return mMaxX;
	}

	/**
	 * Returns the maximum value on the Y axis.
	 * @return the Y axis maximum value
	 */
	public double getMaxY()
	{
		return mMaxY;
	}
}
